Wilbur l



(N0 Mod'el.)

W. L. SHBPARD. VALVE MEGHANISM POR IS'LEAM PUMPING ENGINES. No. 344,998.Patented July 6, 1886.

- UNITED STATES' @PATENT Ormea.

VILB'UR L. SHEPARD, OF HARTFORD, CONNECTICUT, ASSIGNOR TO I. B. DAVIS itSON, OF SAME PLACE.

VALVE MECHANISM FOR STEAM PUlVlPING-ENGI'NES.

SPECIFICATION forming part of Letters Patent No. 344,998, dated July 6,1886;

Application tiled January Q4, 1585.

To @ZZ whom it may concern:

Be it known that I, WILBUR L. SHEPARD, of Hartford, in the county ofHartford and State of Connecticut, have invented certain Improvements inValve Mechanism for Steam Pumping-Engines, ot' which the following is aspecification. v

My invention relates to an improved construction of the valve mechanismof the steamcyliuders of steam pumping-engines. It has reference moreparticularly to that class of valves which are operated bythe directapplication of steam-pressure thereto, and is designed more especiallyas an improvement on the valve mechanism represented in Letters Patentof the United States granted to John Tregoning, dated July 31, 1877, No.193,736.

The improvement consists, generally speaking, of a piston provided withgrooves or Ypassages which cooperate with passages leading from the endsot the valve-chest to the middle of the cylinder, by which the mainpiston is adapted to serve as a valve to control the admission anddischarge of the steam.

Referring to the drawings, Figure 1 represents a longitudinal verticalsection through the center of a pumping-engine constructed.

on my plan. Fig. 2 is a vertical cross section of the steam-cylinder onthe line m w. Fig. 3 is a sectional view ot' a modified form of thepiston,having ports extended through the sime in place of grooves formedin the circumference.

Referring to the drawings, A represents the pumping'cylinder or pumpproper, and B the steam-cylinder by which the pump is actuated. The pumpis provided with the usual ports, valves, and reciprocatingpumping-piston, a, which latter is connected in the ordinary manner by apiston-rod, b, to the steampiston c, from which it receives motion. Thesteam-piston is arranged to reciprocate in the steam-cylinder B, and isprovided near its respective ends with circumferential grooves c c',which serve as ports to permit the escape of exhauststeam, ashereinafter explained. At the top of the cylinder there is located acylindrical valve-chest containing an ordinary slide-valve, g,andcommunicating through induction-'ports h h', controlled by the valve,

Serial No. 153,847, (No model.)

with opposite ends of the cylinder (l. Sepa rate eduction-ports it areextended from the respective ends ot' the cylinder to the space oropening on the inner face. of the main valve'g, the movement of whichconnects said ports alternately with the exhaust-passage j, located atthe middle of the cylinder and leading outward, as represented in Fig.2. The valve g is operated by means of the piston k, located in thevalve-chest, and moved to and fro therein by steam admitted behind itsopposite ends. This piston is recessed on the under side so as to have alimited motion independent ot' the valve g, which is encoun- 1 to andfro. Small openings m m are extended from the central opening in thepiston 7c to opposite ends of the same, for the purpose of admittinglive steam constantly to the two ends of the piston.

The operation of the parts is as follows: Assuming the piston k and mainvalveg to be moved to the right, as represented in Fig. 1, live steamwill enter over the valve and through the port h into the main cylinderat the left of the main piston c, which will be forced to the right, asshown. During this movement of the Vpiston the dead steam will escapefrom the right hand of the main cylinder through the exhaust-port fi,and thence through the under side of the main valve g to thedischarge-passage j. This escape continues until the end of the pistonpasses the mouth of the port t" and closes the same, whereupon theremainingsteam confined in the end of the cylinder andin thedischarge-port h will serve as a cushion to arrest the motion of thepiston. Just before the piston completes its movement the groove ein itsleft end will be brought into position to connect the discharge passagej with the mouth 0l' the port Z,leading to the valve-chamber. Theinstant that this IOO communication is established the steam will bepermitted to escape from the left of piston k, which is thus relievedfrom pressure. At the same time that this relief occurs live steampasses through the port m against the right end of piston k, which atthis time closes the mouth of the port l', in consequence of which thesteam-pressure causes the piston k to be moved to the left, so as toeffect a like movement of the main valve, which is followed by theadmission of live steam through the port h to the right hand of the mainpiston, and a discharge of the dead steam from the opposite end of thesame through the port '12. In due time the steam is discharged from theright of the piston k, and the movement of the parts again reversed. Theparts of the two ends of the cylinder are duplicates of each other, andthe movements to the right and left occur in like manner.

Although it is preferred to employ separate induction and eductionportsh h', it is to be distinctly understoodl that a single port may beused in connection with an ordinary 'D- valve, -this construction beingcommon in steam-engines and pumpingf machinery and: familiar to everyperson skilled in the art.

While I prefer to employ asolid piston provided with circumferentialgrooves, it is tobe understood that the hollow piston provided withports to communicate with the passages j', Z, and l may be employed.This construc-- tion is represented in Fig. 3. y

It will of course be understood bythe skilled,y mechanic that myimprovements are applica-l ble to pumping-enginesof any and all forms inwhich a reciprocating piston is employed.V

It is to be understood that the essence of myinvention lies in theemployment of the piston with channels or ports therein, in combinationwith ports adapted to register therewith, and extending to the valvemechanism, so that the main piston will operate directly to control theiiow of steam through the exhaust-ports from behind the valve-operatingpiston, and it will be manifest to the skilled engineer that thisfeature may be used in connection with valve mechanism of variousconstruetions.

In order that the pump may be started or the motion of the piston may beinstantly reversed at any time, I mount in the valve-chest a rock-shafthaving an eccentric portion to act upon the valve-piston k and move thesame to the right or left, according to the direction in which the shaftis turned. This shaft is inserted through a hole in one sideof the chestand confined by a collar or plug screwed into the chest. The plug bearsat the inner end against a conical collar in the shaft, and the twosurfaces are ground together in such manner as to produce a steam-tightjoint, and thus avoid the use of packing. rlhe inner end of the shaft isseated in a hole in the side of the chest.

Having thus described my invention, what I claim is l. The main cylinderprovided with steamports opening into its ends, and the main pisuatingpiston, the chest or cylinder containing said piston and communicatingat both ends with the steam-supply, and also communicating at each end bv an exhaust or discharge port with the main cylinder, the last-namedports being arranged to register with the two passages of the mainpiston alternately, whereby the main piston is caused to control thedischarge of the steam from behind the valve-actuating piston.

2. In a steam-engi-ne, a valve-actuating piston, and an inclosing chestor cylinder having its two ends in constant communication with thesteam-supply, in combination with the main cylinder provided with theoutlet-ports leading to opposite ends of the valve-chest and arranged tobe closed alternately by the valve-piston, and the main piston providednear its ends with the exhaust-passages arranged to communicatealternately with said ports from the valve-piston and permit thedischarge ofthe steam from the two sides of the valve mechanismalternately. V

3. Ina steam-engine, and in combination with a valveactuating piston,the main cylinder communicating at its middle by two ports with oppositeends of the valve-piston, and

the umili piston provided near its ends with exhaust-steam passagesadapted to register alternately with said ports and connect the samewith the discharge-opening.

4. The main cylinder provided with separate inlet and outlet ports ateach end, the slide-valve controlling said ports, the valvepistonsupplied constantly with live steam at both ends, the valve-actuatingpiston having a limited motion independent of the valve, the twodischarge-ports leading from opposite ends of the valve-chest to themiddle of the main cylinder and adapted to he closed by thevalve-actuating piston, and the main piston provided with theexhaust-passages near its two ends.

5. In combination wit-h the main piston and cylinder and the m'ain valve(1, the actuatingpiston k, having a. limited motionindependent ofthevalve, and the rock-shaft movable at will to change the position of thepiston, whereby the starting of the engine may be effected.

` In testimony whereof I hereunto set my hand this 26th day of December,1884, in the presence of two attesting witnesses.

WILBUR L. SHEPARD.

Witnesses:

HUBERT M. FULLER, PHILIP S. BARNES.

ICO

